Motorola MPC860 PowerQUICC User Manual page 865

Table 33-3 describes the SMASK Þelds.
Bits Name
0Ð3 Ñ Reserved. Should be 0.
4 F Fault.
0 FAULT status line is ignored.
1 FAULT status line is checked during transmission. If a fault occurs, indication is given in TxBD[F] and
a TXE event is generated in the PIPE.
5 PE Paper error.
0 PERROR status line is ignored.
1 PERROR status line is checked during transmission. If a paper error occurs, indication is given in
TxBD[PE] and a TXE event is generated in the PIPE.
6 S Select error.
0 SELECT status line is ignored.
1 SELECT status line is checked during transmission. If a select error occurs, indication is given in
TxBD[S] and a TXE event is generated in the PIPE.
7 Ñ Reserved. Should be 0.
33.3.2 PIP Receiver Parameter RAM
The PIP receiver uses the parameter RAM mapping shown in Table 33-4. Certain parameter
RAM values must be initialized before the receiver is enabled; others are initialized or
written by the CP. Most software does not need access to parameter RAM values after
initialization because activity centers around the buffer descriptors.
Table 33-4. PIP Receiver Parameter RAM Memory Map
1
Offset Name
0x00 RBASE
0x02 Ñ
0x04 PFCR
0x05 Ñ
0x06 MRBLR
0x08 RSTATE
0x0C R_PTR
0x10 RBPTR
0x12 R_CNT
MOTOROLA
Table 33-3. SMASK Field Descriptions
Width
Hword PIP Rx BD table base offset from the beginning of dual-port RAM. Initialize
RBASE before enabling the channel. RBASE should be divisible by 8.
Hword Reserved for transmitting.
Byte PIP function code. This value appears on AT[1-3] when the associated SDMA
channel accesses memory. Also controls byte ordering for the transfers. See
Section 33.3.1.1, ÒPIP Function Code Register (PFCR).Ó
Byte Reserved for transmitting.
Hword Maximum receive buffer length.
Word Rx internal state.
Word Rx internal data pointer.
Hword RxBD pointer. Points to the current Rx BD being processed or to the next BD to
be serviced when idle. After reset or when the end of the Rx BD table is
reached, the CP initializes RBPTR to the RBASE value. Most applications
should not modify RBPTR, but it can be updated if the receiver is disabled or if
no Rx buffer is in use.
Hword Rx internal byte count.
Chapter 33. Parallel Interface Port
Part V. The Communications Processor Module
Description
Description
33-5